1. Field of the Invention
The present invention relates to a solid-state image sensor.
2. Description of Related Art
The pixels in a standard solid-state image sensor in the related art may each include a single photoelectric conversion unit, with a color filter in one of three colors (R, G and B) disposed on each pixel. In such a solid-state image sensor, an R color signal, a G color signal or a B color signal is obtained from a given photoelectric conversion unit.
The solid-state image sensor disclosed in Japanese Laid Open Patent Publication No. 2006-165362 is distinct from the image sensor described above in that at least some of its pixels are equipped with two or more photoelectric conversion units disposed in alignment with one another along the direction in which light enters. Namely, this solid-state image sensor comprises a pixel A equipped with photoelectric conversion units constituted with at least two PN junction portions formed along the depth of a semiconductor substrate, a pixel B equipped with a photoelectric conversion unit constituted with at least one PN junction portion, a first color filter disposed on the pixel A, a second color filter disposed on the pixel B and a detection means for detecting a first color signal and a second color signal from the two PN junction portions at the pixel A and detecting a third color signal from the PN junction portion at the pixel B. A first color signal, a second color signal or a third color signal is obtained from a given photoelectric conversion unit in the solid-state image sensor.